The NIRSPEC H-Band Radial Velocity Templates

NIRSPEC on Keck II

The Keck II NIRSPEC H-band radial velocity (RV) standards found here were obtained with the intent to use in two-dimensional cross-correlation of spectroscopic binaries. Zucker & Mazeh (1994) developed the algorithm to derive RVs of two components simultaneously of composite spectra. Lisa Prato and Michal Simon established a survey in 2000 of pre-main sequence (PMS), single-lined spectroscopic binaries (SB1s). We originally used Zucker & Mazeh's TODCOR software with these template spectra but later developed our own versions of two-dimensional cross-correlation code at Stony Brook by Bender (2006) and at Lowell Observatory by L. Wasserman (see links below).

Our goal is to build up a large sample of PMS double-lined spectroscopic binaries (SB2s) with dynamically measured mass ratios. The precise measurements of mass ratios in young spectroscopic binaries provide critical input for theories of star formation and models of young star evolution.

Most of the standards listed below were used for analysis in the following papers:

• Karnath et al. 2013, submitted
• Torres et al. 2013
• Simon et al. 2013
• Ruiz et al. 2013
• Schaefer et al. 2012
• Mace et al. 2012
• Rosero et al. 2011
• Mace et al. 2009
• Schaefer et al. 2008
• Prato 2007
• Simon et al. 2006
• Rice et al. 2006
• Bender et al. 2005
• Simon & Prato 2004
• Mazeh et al. 2003
• Prato et al. 2002b
• Prato et al. 2002a

We hope you find these spectra useful for your research --- if you do use them, please reference Bender et al. 2005 and/or Prato et al. 2002a.

All RV templates were obtained with NIRSPEC in high-resolution (R~30,000) mode on the Keck II 10-m telescope on Mauna Kea. The observations were made between 2000 June and 2012 January. Typical integration times ranged from 30 seconds to 240 seconds depending on the seeing conditions and stellar magnitude. The NIRSPEC-5 filter was used for all observations. For all data reduction the software package REDSPEC was used. REDSPEC, written at UCLA by S. Kim, L. Prato, and I. McLean, was created specifically for the analysis of NIRSPEC data. Most of the data reduction was carried out by Dara Norman, Chad Bender, and Lisa Prato. Contributions were also made by Nicole Karnath, Dary Ruiz, Greg Mace, and Viviana Rosero.

The radial velocity template downloads can be found below. The object names are linked to files which provide the observed wavelength and normalized flux. The file headers include the JD date of observation, the barycentric RV correction (v_bary), the inherent RV (v_rad), and the name of the object. To correct the observed wavelength (ol) to a vacuum wavelength (vl) scale, vl = ol * ((v_bary - v_rad) / c) where c = speed of light.

Plots in pdf (P) and jpeg (J) format are provided for all spectra. Two spectral types are listed in the table below: one from SIMBAD and a second determined here (see also Prato 2007). For the RV values, the spectra headers list the RV from Chubak et al. (2012) if available or else Nidever et al. (2002) if available. Some RVs for very low mass objects were taken from Blake et al. (2010). Otherwise we calculated the RV from one-dimensional cross-correlation with objects of similar spectral type and known RV.